This is yet another demonstration of the rapid advances taking place in both battery technologies and solar panel efficiency. A few years ago, I was not particularly optimistic about the medium term prospects for large scale replacement of coal, gas and nuclear power generation by solar. I am more hopeful today.

What has surprised me is that there has been no real attempt to move the launch platform up to 80,000 feet or so using gas balloon technology. I would have thought this would be feasible, and could result in a substantial fuel saving.

The video criticizes the lack of definition in a high res shot taken of Pluto from 9 million miles away on July 3. Seriously, let's see how much detail we could get of our moon using a small telescope from that kind of distance.

1. Prevent a nuclear arms race in the Middle East. At least Saudi Arabia and possibly other states in the region would have started their own programs if Iran's nuclear program had been allowed to progress towards nuclear weapons. The choices were

* The international community does nothing, leading to this arms race

* Military attacks on Iran, probably by Israel, further destabilizing the region, and strengthening extremist groups

* A negotiated agreement that inhibits nuclear weapons development by Iran, and gives the international community clear warning if Iran moves in that direction.

2. Make it easier to partner with Iran in combating Islamic extremist groups in the region, such as ISIS.

Iran, while no friend of Israel and the US, is no worse than most governments in the region and better than many. With the current mayhem being created by Islamic State and other extremist groups, we cannot afford further destabilization of the region. Hold you nose and support the agreement. It is the best option available.

The patent has generated fears of what might happen if an aircraft containing radioactive material as fuel were to crash...

This kind of patent on a general concept acts as a string disincentive to others to invest the resources needed to turn such concepts into practical implementations. Usually, that is undesirable. In this case, some seem to believe strongly that the concept should not be pursued. These people should be celebrating.

First, Iceland did not default on its sovereign debt. Thus, although the consequences I outline below are considerable, they are not as severe as those Greece can expect. The large Icelandic banks failed. They grew far too large on the basis of short term borrowing and speculation in leveraged property assets. This was not Icelandic government debt. However, the Iceland central bank did not have the resources to act as lender of last resort and had to allow the banks to go bankrupt and be restructured. International creditors of the banks ended up being shafted, and international arbitration confirmed the Iceland bankruptcy court's right to impose this, even though domestic creditors were protected.

Now for the relatively limited consequences. The capitalization of the Iceland stock market fell 90%. The country was in recession from 2007-2010. Capital controls were imposed that are still in force. 1-2% of the country's population demonstrated regularly and vigorously, forcing the government's resignation.

For Iceland, this was not totally catastrophic, although unpleasant. Greece, with huge sovereign debts already in partial default, will be in no position to restore the banking system following a collapse. Without a deal with its creditors, the economy is going to completely grind to a halt. Aid agencies are going to need to set up soup kitchens and provide health care. I anticipate a dual currency system. The euro will still be used for international transactions, but euros will be extremely scarce and access to them subject to strict government control. Bank deposits will be forcibly converted to drachmas at a notional 1:1 exchange rate. The drachma to euro exchange rate on the black market will quickly rise to tens, hundreds or thousands to one. Inflation will become a severe or catastrophic problem.

Note that with all the costs of restoring the banking system and stimulating the economy to recover from the recession, Iceland's sovereign debt-to-GDP ratio never exceeded 85% and is now down to a very manageable 60%.

I think much of your analogy is flawed, but accepting it at face value, the correct move now is to sell the house that is inappropriate for the family's financial circumstances, and move into an apartment or much smaller house. If this solution is refused, the creditors (in this situation, I am sure the family has other debts) are within their rights to seize the family's assets, including the house, and leave the family to fester.

In most countries, there is a bankruptcy process that can ameliorate the consequences somewhat. There is no bankruptcy process for countries so, if they upset their creditors too much, they can expect truly unpleasant consequences.

Valid point on the acknowledged $1,000,000,000,000 program cost. I would only point out that this cost will inevitably increase over time if the program continues.

Your assumption that the US economy will continue to steadily grow over the next 20 odd years is not conservative, but arguably optimistic.

Whether the F-35 is a powerful weapon is open to debate. Certainly, one could question whether the money could be better spent elsewhere. For instance, a trillion dollars will buy about 250,000 Predator drones.

There is some ceiling on US military spending beyond which they will not be allowed to go. This portion of this for weapons needs to be split in some manner between weapons necessary to enforce US foreign policy, and weapons spending with domestic political benefits. At the time the JSF boondoggle was getting underway, it seemed the US would be facing weak opposition in conflicts. That allowed spending on combat weapons to be restricted, and more to be allocated towards pork barrel projects like the JSF. Indeed, with less projected need for weapons used in warmongering, projects like the JSF were important to keep military spending near its permitted ceiling. The situation is now a bit different. To support US foreign policy, a credible deterrent against a resurgent Russia and increasingly aggressive China is now needed. The JSF may need to go to free up cash for real weapons systems.

In general, I think the point about large charities being mostly about sustaining themselves is correct. However, they have connections that can often make them the only (albeit imperfect) organizations that can mobilize relief after major disasters. Further, some specific large charities provide unique services that smaller organizations, however well run, cannot replicate. An example is the Red Cross and their monitoring of prisoners of war. I also greatly respect one or two large charities. Médecins Sans Frontières (Doctors Without Borders) does tremendous work, such as fighting the ebola outbreak for months before the WHO did anything effective.. Generalizations can have limited validity, but must not be taken too far

It is easy to explain why an experiment failed after the event, but that does not mean the result was obvious. This is a case in point. Had the experiment succeeded, cheaper, safer food with reduced environmental impact would have been possible. Sadly, it failed. Now, we need to look at other approaches.

With a mobile device (which most Android devices are) that are continually switching between networks, static IP addresses are not ideal. The "static" IP address (for most protocols) needs to be routable. This means the address must change when switching networks. Support for DHCPv6 is arguably the easiest way to do this. Having routers need to recognize when random addresses are generated inside their networks and correctly route them without security concerns is not ideal.

Apart from the obvious stench of corrupt commercial dealings, we should not forget that data collection by law enforcement has not always been for crime fighting purposes. Recall, for instance, J Edgar Hoover's uses for such data.